'Breaches' are either development without planning permission or development that fails to obey conditions attached to a planning permission.
Conditions that apply will be spelt out with any relevant decision to grant planning permission.
You can check the council's register of planning applications if you suspect a breach of a condition.
Unauthorised travellers' sites often attract a lot of media attention, but there are other breaches of planning controls that can often be far more damaging to the countryside, such as removing protected trees, failing to do surveys on sites of possible archaeological interest and large-scale tipping of waste.
In some cases those responsible for development will look to make it lawful without applying for planning permission. They can do this through applying for a lawful use certificate, for either an existing use of land (a CLEUD) or a proposed use (a CLOPUD).
Local authorities cannot look at the merits of a case for a lawful use certificate, only on whether lawfulness has been proved.
In the case of CLEUDs, much will depend on whether the developer can prove that the use has become established, i.e. it has happened on a permanent basis over a 10 year period. If it is able to prove this, then the local planning authority must grant the certificate.
You can put forward evidence that the use has not existed for less than 10 years and/or less than 28 days in any year; or highlight any contradictions that may exist in the applicant's evidence. You will need to provide tangible proof of your points. Legal precedents have confirmed that if there are any contradictions in the applicant's evidence on any relevant issues, then the local authority is entitled to refuse to grant a certificate.
If the authority has to grant a certificate, it is possible to place restrictions on what it allows. Government advice in Circular 10/97, Annex 8 (particularly paragraphs 8.16 - 8.21) states that certificates should be as precisely worded as possible. You can look to ensure that any use, beyond what has already happened consistently over the last 10 years, is not covered by the certificate.
If the application is refused, you may also need to consider pressing for enforcement action if the use continues.